Octafluorobutane compositions

ABSTRACT

The present invention includes compositions of octafluorobutane and a compound of the formula C a  F b  H 2a+2-b , where a=3 or 4 and b=1 to 8 are disclosed. These compositions, which may be azeotropic or azeotrope-like, may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents or displacement drying agents.

FIELD OF THE INVENTION

This invention relates to compositions that include an octafluorobutane. These compositions are useful as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as a refrigerant. Such refrigerants include trichlorofluoromethane (CFC-11) and chlorofifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds of fluorinated hydrocarbon refrigerants released into the atmosphere may adversely affect the stratospheric ozone layer. Although this proposition has not yet been completely established, there is a movement toward the control of the use and the production of certain chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under an international agreement.

Accordingly, there is a demand for the development of refrigerants that have a lower ozone depletion potential than existing refrigerants while still achieving an acceptable performance in refrigeration applications. Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCs and HCFCs since HFCs have no chlorine and therefore have zero ozone depletion potential.

In refrigeration applications, a refrigerant is often lost during operation through leaks in shaft seals, hose connections, soldered joints and broken lines. In addition, the refrigerant may be released to the atmosphere during maintenance procedures on refrigeration equipment. If the refrigerant is not a pure component or an azeotropic or azeotrope-like composition, the refrigerant composition may change when leaked or discharged to the atmosphere from the refrigeration equipment, which may cause the refrigerant to become flammable or to have poor refrigeration performance.

Accordingly, it is desirable to use as a refrigerant a single fluorinated hydrocarbon or an azeotropic or azeotrope-like composition that includes one or more fluorinated hydrocarbons.

Fluorinated hydrocarbons may also be used as a cleaning agent or solvent to clean, for example, electronic circuit boards. It is desirable that the cleaning agents be azeotropic or azeotrope-like because in vapor degreasing operations the cleaning agent is generally redistilled and reused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinated hydrocarbon are also useful as blowing agents in the manufacture of closed-cell polyurethane, phenolic and thermoplastic foams, as propellants in aerosols, as heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids such as for heat pumps, inert media for polymerization reactions, fluids for removing particulates from metal surfaces, as carrier fluids that may be used, for example, to place a fine film of lubricant on metal parts, as buffing abrasive agents to remove buffing abrasive compounds from polished surfaces such as metal, as displacement drying agents for removing water, such as from jewelry or metal parts, as resist developers in conventional circuit manufacturing techniques including chlorine-type developing agents, or as strippers for photoresists when used with, for example, a chlorohydrocarbon such as 1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of refrigerant compositions of octafluorobutane and a compound of the formula C_(a) F_(b) H_(2a+2-b), where a=3 or 4 and b=1 to 8. These compositions are also useful as cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents. Further, the invention relates to the discovery of binary azeotropic or azeotrope-like compositions comprising effective amounts of octafluorobutane and a compound of the formula C_(a) F_(b) H_(2a+b-b), where a=3 or 4 and b=1 to 8, to form an azeotropic or azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-245ca at 25° C.;

FIG. 2 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-245ea at 25° C.;

FIG. 3 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-245eb at 25° C.;

FIG. 4 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-254ca at 25° C.;

FIG. 5 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-338mee at 25° C.;

FIG. 6 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338q and HFC-356mff at 25° C.;

FIG. 7 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mee and HFC-245ca at 25° C.;

FIG. 8 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mee and HFC-245ea at 25° C.;

FIG. 9 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mee and HFC-254ca at 25° C.;

FIG. 10 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mee and HFC-356mff at 25° C.;

FIG. 11 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-245ca at 25° C.;

FIG. 12 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-245ea at 25° C.;

FIG. 13 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-245eb at 25° C.;

FIG. 14 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-254ca at 25° C.;

FIG. 15 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-263ca at 25° C.;

FIG. 16 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-272ea at 25° C.;

FIG. 17 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338mf and HFC-272fb at 25° C.; and

FIG. 18 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-338pcc and HFC-272ea at 25° C.

DETAILED DESCRIPTION

The present invention relates to compositions of octafluorobutane and a compound of the formula C_(a) F_(b) H_(2a+2-b), where a=3 or 4 and b=1 to 8. The isomers of octafluorobutane include 1,1,1,2,2,3,3,4-octafluorobutane (HFC-338 q), 1,1,1,2,3,4,4,4-octafluorobutane (HFC-338mee), 1,1,1,2,2,4,4,4-octafluorobutane (HFC-338mf) and 1,1,2,2,3,3,4,4-octafluorobutane (HFC-338pcc). Examples of these compositions include:

(a) HFC-338q and HFC-338mee, 1,1,2,2,3-pentafluoropropane (HFC-245ca), 1,1,2,3,3-pentafluoropropane (HFC-245ea), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,2,2,3-tetrafluoropropane (HFC-254ca) or 1,1,1,4,4,4-hexafluorobutane (HFC-356mff); or

(b) HFC-338mee and 1,1,2,2,3-pentafluoropropane (HFC-245ca), 1,1,2,3,3-pentafluoropropane (HFC-245ea), 1,2,2,3-tetrafluoropropane (HFC-254ca), 1,1,1,4,4,4-hexafluorobutane (HFC-356mff); or

(c) HFC-338mf and 1,1,2,2,3-pentafluoropropane (HFC-245ca), 1,1,2,3,3-pentafluoropropane (HFC-245ea), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,2,2,3-tetrafluoropropane (HFC-254ca), 1,2,2-trifluoropropane (HFC-263ca), 1,2-difluoropropane (HFC-272ea), 1,1-difluoropropane (HFC-272fb); or

(d) HFC-338pcc and 1,2-difluoropropane (HFC-272ea).

1,1,1,2,2,3,3,4-octafluorobutane (HFC-338q, CF₃ CF₂ CF₂ CH₂ F, CAS Reg. No. [662-35-1]) has been prepared by the reaction of 1,1,1,2,2,3,3,-heptafluorobutanol with phosgene and hydrogen fluoride as disclosed by Nappa, et. al. in U.S. Pat. No. 5,274,189.

1,1,1,2,3,4,4,4-octafluorobutane (HFC-338mee, CF₃ CHFCHFCF₃, CAS Reg. No. [75995-72-1]) has been prepared by the hydrogenation of perfluoro-2-butene over a palladium on alumina catalyst as reported by Hudlicky, et. al. in Journal of Fluorine Chemistry Vol. 59, pp. 9-14 (1992).

1,1,1,2,2,4,4,4-octafluorobutane (HFC-338mf, CF₃ CH₂ CF₂ CF₃, CAS Reg. No. [2924-29-0]) has been prepared by photolyzing a mixture of 1,2-difluoroethylene and pentafluoroethyl iodide to give CF₃ CF₂ CH₂ CF₂ I followed by fluorination of the fluoroiodobutane with mercurous fluoride to give CF₃ CF₂ CH₂ CF₃ as reported by Haszeldine, et. al. in Journal of the Chemical Society, pp. 3005-3009 (1955).

1,1,2,2,3,3,4,4-octafluorobutane, CF₂ HCF₂ CF₂ CF₂ H, HFC-338pcc, may be made by refluxing the potassium salt of perfluoroadipic acid in ethylene glycol as reported by Hudlicky, et. al. in J. Fluorine Chemistry, Vol. 59, pp. 9-14 lS (1992).

1-99 wt. % of each of the components of the compositions can be used as refrigerants. Further, the present invention also relates to the discovery of azeotropic or azeotrope-like compositions of effective amounts of each of the above mixtures to form an azeotropic or azeotrope-like composition.

By "azeotropic" composition is meant a constant boiling liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without compositional change. Constant boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, as compared with that of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, or substantially constant boiling, liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotrope-like composition is that the vapor produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without substantial composition change. Another way to characterize an azeotrope-like composition is that the bubble point vapor pressure and the dew point vapor pressure of the composition at a particular temperature are substantially the same.

It is recognized in the art that a composition is azeotrope-like if, after 50 weight percent of the composition is removed such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is less than 10 percent, when measured in absolute units. By absolute units, it is meant measurements of pressure and, for example, psia, atmospheres, bars, torr, dynes per square centimeter, millimeters of mercury, inches of water and other equivalent terms well known in the art. If an azeotrope is present, there is no difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed.

Therefore, included in this invention are compositions of effective amounts of:

(a) HFC-338q and HFC-338mee, HFC-245ca, HFC-245ea, HFC-

245eb, HFC-254ca or HFC-356mff; or

(b) HFC-338mee and HFC-245ca, HFC-245ea, HFC-254ca, HFC-

356mff; or

(c) HFC-338mf and HFC-245ca, HFC-245ea, HFC-245eb, HFC-

254ca, HFC-263ca, HFC-272ea, HFC-272fb; or

(d) HFC-338pcc and HFC-272ea;

such that after 50 weight percent of an original composition is evaporated or boiled off to produce a remaining composition, the difference in the vapor pressure between the original composition and the remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range of compositions around the azeotrope point that, for a maximum boiling azeotrope, have boiling points at a particular pressure higher than the pure components of the composition at that pressure and have vapor pressures at a particular temperature lower than the pure components of the composition at that temperature, and that, for a minimum boiling azeotrope, have boiling points at a particular pressure lower than the pure components of the composition at that pressure and have vapor pressures at a particular temperature higher than the pure components of the composition at that temperature. Boiling temperatures and vapor pressures above or below that of the pure components are caused by unexpected intermolecular forces between and among the molecules of the compositions, which can be a combination of repulsive and attractive forces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling point at a particular pressure, or a maximum or minimum vapor pressure at a particular temperature, may or may not be coextensive with the range of compositions that have a change in vapor pressure of less than about 10% when 50 weight percent of the composition is evaporated. In those cases where the range of compositions that have maximum or minimum boiling temperatures at a particular pressure, or maximum or minimum vapor pressures at a particular temperature, are broader than the range of compositions that have a change in vapor pressure of less than about 10% when 50 weight percent of the composition is evaporated, the unexpected intermolecular forces are nonetheless believed important in that the refrigerant compositions having those forces that are not substantially constant boiling may exhibit unexpected increases in the capacity or efficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the following vapor pressures at 25° C.

    ______________________________________                                         COMPONENTS    PSIA            KPA                                              ______________________________________                                         HFC-338q      14.7            101                                              HFC-338mee    14.7            101                                              HFC-338mf     18.8            130                                              HFC-338pcc    6.9             48                                               HFC-245ca     14.2            98                                               HFC-245ea     8.6             59                                               HFC-245eb     16.9            117                                              HFC-254ca     13.7            94                                               HFC-356mff    14.7            101                                              HFC-263ca     18.2            125                                              HFC-272ea     20.8            143                                              HFC-272fb     26.5            183                                              ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-like compositions of this invention comprise the following (all compositions are measured at 25° C.):

    ______________________________________                                                         WEIGHT                                                                         RANGES       PREFERRED                                         COMPONENTS      (wt. %/wt/%) (wt. %/wt. %)                                     ______________________________________                                         HFC-338q/HFC-245ca                                                                             1-99/1-99    30-99/1-70                                        HFC-338q/HFC-245ea                                                                             1-51/49-99   1-51/49-99                                        HFC-338q/HFC-245eb                                                                             1-99/1-99    1-99/1-99                                         HFC-338q/HFC-254ca                                                                             1-99/1-99    40-99/1-60                                        HFC-338q/HFC-338mee                                                                            1-99/1-99    20-80/20-80                                       HFC-338q/HFC-356mff                                                                            1-99/1-99    20-99/1-80                                        HFC-338mee/HFC-245ca                                                                           1-99/1-99    40-99/1-60                                        HFC-338mee/HFC-245ea                                                                           1-51/49-99   1-51/49-99                                        HFC-338mee/HFC-254ca                                                                           1-99/1-99    60-99/1-40                                        HFC-338mee/HFC-356mff                                                                          1-99/1-99    30-99/1-70                                        HFC-338mf/HFC-245ca                                                                            1-99/1-99    50-99/1-50                                        HFC-338mf/HFC-245ea                                                                            68-99/1-32   68-99/1-32                                        HFC-338mf/HFC-245eb                                                                            1-99/1-99    50-99/1-50                                        HFC-338mf/HFC-254ca                                                                            53-99/1-47   60-99/1-40                                        HFC-338mf/HFC-263ca                                                                            1-99/1-99    60-99/1-40                                        HFC-338mf/HFC-272ea                                                                            1-91/9-99    60-91/9-40                                        HFC-338mf/HFC-272fb                                                                            1-99/1-99    10-99/1-90                                        HFC-338pcc/HFC-272ea                                                                           1-41/59-99   1-41/59-99                                        ______________________________________                                    

For purposes of this invention, "effective amount" is defined as the amount of each component of the inventive compositions which, when combined, results in the formation of an azeotropic or azeotrope-like composition. This definition includes the amounts of each component, which amounts may vary depending on the pressure applied to the composition so long as the azeotropic or azeotrope-like compositions continue to exist at the different pressures, but with possible different boiling points.

Therefore, effective amount includes the amounts, such as may be expressed in weight percentages, of each component of the compositions of the instant invention which form azeotropic or azeotrope-like compositions at temperatures or pressures other than as described herein.

For the purposes of this discussion, azeotropic or constant-boiling is intended to mean also essentially azeotropic or essentially-constant boiling. In other words, included within the meaning of these terms are not only the true azeotropes described above, but also other compositions containing the same components in different proportions, which are true azeotropes at other temperatures and pressures, as well as those equivalent compositions which are part of the same azeotropic system and are azeotrope-like in their properties. As is well recognized in this art, there is a range of compositions which contain the same components as the azeotrope, which will not only exhibit essentially equivalent properties for refrigeration and other applications, but which will also exhibit essentially equivalent properties to the true azeotropic composition in terms of constant boiling characteristics or tendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixture which may appear under many guises, depending upon the conditions chosen, by any of several criteria:

* The composition can be defined as an azeotrope of A, B, C (and D . . . ) since the very term "azeotrope" is at once both definitive and limitative, and requires that effective amounts of A, B, C (and D . . . ) for this unique composition of matter which is a constant boiling composition.

* It is well known by those skilled in the art, that, at different pressures, the composition of a given azeotrope will vary at least to some degree, and changes in pressure will also change, at least to some degree, the boiling point temperature. Thus, an azeotrope of A, B, C (and D . . . ) represents a unique type of relationship but with a variable composition which depends on temperature and/or pressure. Therefore, compositional ranges, rather than fixed compositions, are often used to define azeotropes.

* The composition can be defined as a particular weight percent relationship or mole percent relationship of A, B, C (and D . . . ), while recognizing that such specific values point out only one particular relationship and that in actuality, a series of such relationships, represented by A, B, C (and D . . . ) actually exist for a given azeotrope, varied by the influence of pressure.

* An azeotrope of A, B, C (and D . . . ) can be characterized by defining the compositions as an azeotrope characterized by a boiling point at a given pressure, thus giving identifying characteristics without unduly limiting the scope of the invention by a specific numerical composition, which is limited by and is only as accurate as the analytical equipment available.

The azeotrope or azeotrope-like compositions of the present invention can be prepared by any convenient method including mixing or combining the desired amounts. A preferred method is to weigh the desired component amounts and thereafter combine them in an appropriate container.

Specific examples illustrating the invention are given below. Unless otherwise stated therein, all percentages are by weight. It is to be understood that these examples are merely illustrative and in no way are to be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following compositions are azeotropic. The temperature is 25° C.

    ______________________________________                                                                Vapor Press.                                            Composition     Weight Percents                                                                             psia     kPa                                      ______________________________________                                         HFC-338q/HFC-245ca                                                                             62.1/37.9    13.0     90                                       HFC-338q/HFC-245ea                                                                             32.9/67.1    6.4      44                                       HFC-338q/HFC-245eb                                                                              5.5/94.5    16.9     117                                      HFC-338q/HFC-254ca                                                                             77.0/23.0    15.2     105                                      HFC-338q/HFC-338mee                                                                            50.3/49.7    14.9     103                                      HFC-338q/HFC-356mff                                                                            49.5/50.5    16.4     113                                      HFC-338mee/HFC-245ca                                                                           63.0/37.0    12.8     88                                       HFC-338mee/HFC-245ea                                                                           33.0/67.0    6.3      43                                       HFC-338mee/HFC-254ca                                                                           95.4/4.6     14.7     101                                      HFC-338mee/HFC-356mff                                                                          47.1/52.9    17.5     121                                      HFC-338mf/HFC-245ca                                                                            88.0/12.0    20.1     139                                      HFC-338mf/HFC-245ea                                                                            95.0/4.5     19.1     132                                      HFC-338mf/HFC-245eb                                                                            71.2/28.8    23.4     161                                      HFC-338mf/HFC-254ca                                                                            80.0/20.0    22.8     157                                      HFC-338mf/HFC-263ca                                                                            71.8/28.2    21.8     150                                      HFC-338mf/HFC-272ea                                                                            73.2/26.8    27.0     186                                      HFC-338mf/HFC-272fb                                                                            23.4/76.6    26.7     184                                      HFC-338pcc/HFC-272ea                                                                            3.5/96.5    20.8     144                                      ______________________________________                                    

EXAMPLE 2

Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial liquid composition at 25° C. The liquid, and the vapor above the liquid, are allowed to come to equilibrium, and the vapor pressure in the vessel is measured. Vapor is allowed to leak from the vessel, while the temperature is held constant at 25° C., until 50 weight percent of the initial charge is removed, at which time the vapor pressure of the composition remaining in the vessel is measured. The results are summarized below.

    __________________________________________________________________________     Refrigerant   0 wt % evaporated                                                                        50 wt % evaporated                                                                       0% change in                                 Composition   psia kPa  psia kPa  vapor pressure                               __________________________________________________________________________     HFC-338q/HFC-245ca                                                             62.1/37.9     13.0 90   13.0 90   0.0                                          80/20         13.3 92   13.2 91   0.8                                          99/1          14.6 101  14.6 101  0.0                                          40/60         13.2 91   13.2 91   0.0                                          20/80         13.7 94   13.6 94   0.7                                          1/99          14.2 98   14.2 98   0.0                                          HFC-338q/HFC-245ea                                                             32.9/67.1     6.4  44   6.4  44   0.0                                          15/85         7.4  51   6.8  47   8.1                                          10/90         7.9  54   7.2  50   8.9                                          1/99          8.6  59   8.5  59   1.2                                          51/49         7.3  50   6.6  46   9.6                                          52/48         7.4  51   6.6  46   10.8                                         HFC-338q/HFC-245eb                                                             5.5/94.5      16.9 117  16.9 117  0.0                                          1/99          16.9 117  16.9 117  0.0                                          20/80         16.9 117  16.9 117  0.0                                          40/60         16.8 116  16.7 115  0.6                                          60/40         16.5 114  16.4 113  0.6                                          80/20         15.9 110  15.8 109  0.6                                          99/1          14.8 102  14.8 102  0.0                                          HFC-338q/HFC-254ca                                                             77.0/23.0     15.2 105  15.2 105  0.0                                          90/10         15.1 104  15.1 104  0.0                                          99/1          14.8 102  14.7 101  0.7                                          40/60         14.7 101  14.7 101  0.0                                          20/80         14.2 98   14.2 98   0.0                                          1/99          13.7 94   13.7 94   0.0                                          HFC-338q/HFC-338mee                                                            50.3/49.7     14.9 103  14.9 103  0.0                                          80/20         14.8 102  14.8 102  0.0                                          99/1          14.7 101  14.7 101  0.0                                          20/80         14.8 102  14.8 102  0.0                                          1/99          14.7 101  14.7 101  0.0                                          HFC-338q/HFC-356mff                                                            49.5/50.5     16.4 113  16.4 113  0.0                                          20/80         15.9 110  15.7 108  1.3                                          1/99          14.8 102  14.7 101  0.7                                          80/20         15.8 109  15.7 108  0.6                                          99/1          14.8 102  14.8 102  0.0                                          HFC-338mee/HFC-245ca                                                           63.0/37.0     12.8 88   12.8 88   0.0                                          80/20         13.1 90   13.0 90   0.8                                          99/1          14.6 101  14.6 101  0.0                                          40/60         13.1 90   13.1 90   0.0                                          20/80         13.6 94   13.6 94   0.0                                          1/99          14.2 98   14.2 98   0.0                                          HFC-338mee/HFC-245ea                                                           33.0/67.0     6.3  43   6.3  43   0.0                                          5/95          7.3  50   6.7  46   8.2                                          8/92          8.1  56   7.4  51   8.6                                          1/99          8.6  59   8.5  59   1.2                                          51/49         7.2  50   6.5  45   9.7                                          52/48         7.3  50   6.5  45   11.0                                         HFC-338mee/HFC-254ca                                                           95.4/4.6      14.7 101  14.7 101  0.0                                          99/1          14.7 101  14.7 101  0.0                                          60/40         14.4 99   14.4 99   0.0                                          40/60         14.2 98   14.2 98   0.0                                          20/80         14.0 97   13.9 96   0.7                                          1/99          13.7 94   13.7 94   0.0                                          HFC-338mee/HFC-356mff                                                          47.1/52.9     17.5 121  17.5 121  0.0                                          20/80         16.9 117  16.5 114  2.4                                          1/99          14.9 103  14.8 102  0.7                                          60/40         17.4 120  17.3 119  0.6                                          80/20         16.6 114  16.3 112  1.8                                          99/1          14.8 102  14.8 102  0.0                                          HFC-338mf/HFC-245ca                                                            88.0/12.0     20.1 139  20.1 139  0.0                                          99/1          19.2 132  19.0 131  1.0                                          70/30         19.5 134  19.1 132  2.1                                          50/50         18.0 124  17.3 119  3.9                                          30/70         16.4 113  15.8 109  3.7                                          20/80         15.7 108  15.2 105  3.2                                          10/90         14.9 103  14.6 101  2.0                                          1/99          14.3 99   14.2 98   0.7                                          HFC-338mf/HFC-245ea                                                            95.5/4.5      19.1 132  19.1 132  0.0                                          99/1          19.0 131  18.9 130  0.5                                          68/32         17.1 118  15.4 106  9.9                                          67/33         17.0 117  15.2 105  10.6                                         HFC-338mf/HFC-245eb                                                            71.2/28.8     23.4 161  23.4 161  0.0                                          80/20         23.2 160  23.0 159  0.9                                          90/10         22.4 154  21.3 147  4.9                                          99/1          19.6 135  18.9 130  3.6                                          50/50         22.7 157  22.1 152  2.6                                          30/70         21.1 145  19.7 136  6.6                                          20/80         19.9 137  18.6 128  6.5                                          10/90         18.5 128  17.6 121  4.9                                          1/99          17.1 118  17.0 117  0.6                                          HFC-338mf/HFC-254ca                                                            80.0/20.0     22.8 157  22.8 157  0.0                                          90/10         22.5 155  21.9 151  2.7                                          99/1          19.8 137  18.9 130  4.5                                          60/40         22.1 152  21.1 145  4.5                                          53/47         21.0 145  18.9 130  10.0                                         HFC-338mf/HFC-263ca                                                            71.8/28.2     21.8 150  21.8 150  0.0                                          90/10         21.1 145  20.7 143  1.9                                          99/1          19.2 132  19.0 131  1.0                                          50/50         21.3 147  21.1 145  0.9                                          30/70         20.3 140  19.8 137  2.5                                          10/90         19.0 131  18.7 129  1.6                                          1/99          18.3 126  18.3 126  0.0                                          HFC-338mf/HFC-272ea                                                            73.2/26.8     27.0 186  27.0 186  0.0                                          85/15         26.6 183  26.1 180  1.9                                          91/9          25.9 179  23.5 162  9.3                                          92/8          25.6 177  22.8 157  10.9                                         60/40         26.7 184  26.3 181  1.5                                          40/60         25.3 174  24.0 165  5.1                                          20/80         23.2 160  22.0 152  5.2                                          1/99          20.9 144  20.8 143  0.5                                          HFC-338mf/HFC-272fb                                                            23.4/76.6     26.7 184  26.7 184  0.0                                          10/90         26.6 183  26.6 183  0.0                                          1/99          26.5 183  26.5 183  0.0                                          40/60         26.6 183  26.5 183  0.4                                          60/40         25.8 178  25.5 176  1.2                                          80/20         23.8 164  23.0 159  3.4                                          90/10         21.9 151  21.0 145  4.1                                          99/1          19.2 132  19.0 131  1.0                                          HFC-338pcc/HFC-272ea                                                           3.5/96.5      20.8 144  20.8 144  0.0                                          1/99          20.8 143  20.8 143  0.0                                          30/70         20.0 138  18.9 130  5.4                                          40/60         19.2 132  17.4 120  9.5                                          41/59         19.1 131  17.2 118  9.9                                          42/58         19.0 131  17.0 117  10.4                                         __________________________________________________________________________

The results of this Example show that these compositions are azeotropic or azeotrope-like because when 50 wt. % of an original composition is removed, the vapor pressure of the remaining composition is within about 10% of the vapor pressure of the original composition, at a temperature of 25° C.

EXAMPLE 3 Impact of Vapor Leakage at 50° C.

A leak test is performed on compositions of HFC-338pcc and HFC-2ea, at the temperature of 50° C. The results are summarized below.

    __________________________________________________________________________     Refrigerant   0 wt % evaporated                                                                        50 wt % evaporated                                                                       0% change in                                 Composition   psia kPa  psia kPa  vapor pressure                               __________________________________________________________________________     HFC-338pcc/HFC-272ea                                                           5.6/94.4      45.2 312  45.2 312  0.0                                          1/99          45.0 310  45.0 310  0.0                                          30/70         43.7 301  42.1 290  3.7                                          40/60         42.3 292  39.3 271  7.1                                          48/52         40.7 281  36.7 253  9.8                                          49/51         40.4 279  36.3 250  10.1                                         __________________________________________________________________________

These results show that compositions of and are azeotropic or azeotrope-like at different temperatures, but that the weight percents of the components vary as the temperature is changed.

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants in an ideal vapor compression cycle. The data are based on the following conditions.

Evaporator temperature 40.0° F. (4.4° C.)

Condenser temperature 130.0° F. (54.4° C.)

Liquid subcooled 5° F. (2.8° C.)

Return Gas 60° F. (15.6° C.)

Compressor efficiency is 70%.

The refrigeration capacity is based on a compressor with a fixed displacement of 3.5 cubic feet per minute and 70% volumetric efficiency. Capacity is intended to mean the change in enthalpy of the refrigerant in the evaporator per pound of refrigerant circulated, i.e. the heat removed by the refrigerant in the evaporator per time. Coefficient of performance (COP) is intended to mean the ratio of the capacity to compressor work. It is a measure of refrigerant energy efficiency.

    __________________________________________________________________________                   Evap.  Cond.               Capacity                              Refrig.       Press. Press. Comp. Dis.   BTU/min                               Comp.         Psia                                                                               kPa                                                                               Psia                                                                               kPa                                                                               Temp. °F.                                                                     °C.                                                                        COP kw                                    __________________________________________________________________________     HFC-338q/HFC-245ca                                                             1/99          6.2 43 36.7                                                                               253                                                                               165.0 73.9                                                                              3.07                                                                               32.9                                                                              0.6                                99/1          6.6 46 38.6                                                                               266                                                                               136.1 57.8                                                                              2.74                                                                               30.0                                                                              0.5                                HFC-338q/HFC-245ea                                                             1/99          3.5 24 23.7                                                                               163                                                                               176.3 72.6                                                                              3.17                                                                               20.9                                                                              0.4                                99/1          6.5 45 38.5                                                                               265                                                                               136.1 57.8                                                                              2.75                                                                               30.0                                                                              0.5                                HFC-338q/HFC-245eb                                                             1/99          7.6 52 43.1                                                                               297                                                                               163.2 72.9                                                                              3.04                                                                               38.7                                                                              0.7                                99/1          6.6 46 38.7                                                                               267                                                                               136.1 57.8                                                                              3.11                                                                               30.1                                                                              0.5                                HFC-338q/HFC-254ca                                                             1/99          6.0 41 35.3                                                                               243                                                                               169.0 76.1                                                                              3.11                                                                               32.2                                                                              0.6                                99/1          6.6 46 38.7                                                                               267                                                                               136.1 57.8                                                                              2.74                                                                               30.1                                                                              0.5                                HFC-338q/HFC-338mee                                                            1/99          6.5 45 39.0                                                                               269                                                                               138.9 59.4                                                                              2.78                                                                               30.5                                                                              0.5                                99/1          6.5 45 38.5                                                                               265                                                                               135.8 57.7                                                                              2.74                                                                               29.9                                                                              0.5                                HFC-338q/HFC-356mff                                                            1/99          6.5 45 38.3                                                                               264                                                                               142.1 61.2                                                                              2.85                                                                               31.1                                                                              0.5                                99/1          6.5 45 38.5                                                                               265                                                                               135.8 57.7                                                                              2.74                                                                               29.9                                                                              0.5                                HFC-338mee/HFC-245ca                                                           1/99          6.2 43 36.7                                                                               253                                                                               165.0 73.9                                                                              3.07                                                                               32.9                                                                              0.6                                99/1          6.5 45 39.1                                                                               270                                                                               139.2 59.6                                                                              2.78                                                                               30.6                                                                              0.5                                HFC-338mee/HFC-245ea                                                           1/99          3.5 24 23.6                                                                               163                                                                               176.2 80.1                                                                              3.18                                                                               20.9                                                                              0.4                                99/1          6.5 45 39.0                                                                               269                                                                               139.2 59.6                                                                              2.78                                                                               30.5                                                                              0.5                                HFC-338mee/HFC-254ca                                                           1/99          6.0 41 35.3                                                                               243                                                                               169.1 76.2                                                                              3.11                                                                               32.2                                                                              0.6                                99/1          6.5 45 39.2                                                                               270                                                                               139.3 59.6                                                                              2.78                                                                               30.7                                                                              0.5                                HFC-338mee/HFC-356mff                                                          1/99          6.5 45 39.3                                                                               271                                                                               142.1 61.2                                                                              2.85                                                                               31.1                                                                              0.5                                99/1          6.5 45 39.1                                                                               270                                                                               138.9 59.4                                                                              2.78                                                                               30.5                                                                              0.5                                HFC-338mf/HFC-245ca                                                            1/99          6.2 43 36.8                                                                               254                                                                               164.9 73.8                                                                              3.08                                                                               33.1                                                                              0.6                                99/1          8.6 59 48.2                                                                               332                                                                               134.6 57.0                                                                              2.68                                                                               37.1                                                                              0.7                                HFC-338mf/HFC-245ea                                                            1/99          3.5 24 23.7                                                                               163                                                                               176.1 80.1                                                                              3.18                                                                               21.0                                                                              0.4                                99/1          8.6 59 48.1                                                                               332                                                                               134.7 57.1                                                                              2.68                                                                               37.0                                                                              0.7                                HFC-338mf/HFC-245eb                                                            1/99          7.6 52 43.1                                                                               297                                                                               163.3 72.9                                                                              3.04                                                                               38.7                                                                              0.7                                99/1          8.7 60 48.3                                                                               333                                                                               134.6 57.0                                                                              2.68                                                                               37.2                                                                              0.7                                HFC-338mf/HFC-254ca                                                            1/99          6.0 41 35.4                                                                               244                                                                               168.9 76.1                                                                              3.11                                                                               32.3                                                                              0.6                                99/1          8.7 60 48.3                                                                               333                                                                               134.7 57.1                                                                              2.68                                                                               37.2                                                                              0.7                                HFC-338mf/HFC-263ca                                                            1/99          8.4 58 44.9                                                                               310                                                                               169.9 76.6                                                                              3.11                                                                               42.6                                                                              0.8                                99/1          8.7 60 48.5                                                                               334                                                                               134.8 57.1                                                                              2.68                                                                               37.3                                                                              0.7                                HFC-338mf/HFC-272ea                                                            1/99          9.6 66 51.0                                                                               352                                                                               179.6 82.0                                                                              3.15                                                                               49.5                                                                              0.9                                99/1          8.8 61 49.0                                                                               338                                                                               135.0 57.2                                                                              2.68                                                                               37.8                                                                              0.7                                HFC-338mf/HFC-272fb                                                            1/99          12.6                                                                               87 63.6                                                                               439                                                                               177.0 80.6                                                                              3.10                                                                               61.6                                                                              1.1                                99/1          8.9 61 49.2                                                                               339                                                                               134.9 57.2                                                                              2.69                                                                               38.2                                                                              0.7                                HFC-338pcc/HFC-272ea                                                           1/99          9.6 66 50.8                                                                               350                                                                               179.7 82.1                                                                              3.15                                                                               49.2                                                                              0.9                                99/1          3.1 21 21.7                                                                               150                                                                               144.2 62.3                                                                              2.96                                                                               17.2                                                                              0.3                                __________________________________________________________________________      *45° F. Evaporator Temperature, 65° F. Return Gas          

EXAMPLE 5

This Example is directed to measurements of the liquid/vapor equilibrium curves for the mixtures in FIGS. 1-18.

Turning to FIG. 1, the upper curve represents the composition of the liquid, and the lower curve represents the composition of the vapor.

The data for the compositions of the liquid in FIG. 1 are obtained as follows. A stainless steel cylinder is evacuated, and a weighed amount of HFC-338q is added to the cylinder. The cylinder is cooled to reduce the vapor pressure of HFC-338q, and then a weighed amount of HFC-245ca is added to the cylinder. The cylinder is agitated to mix the HFC-338q and HFC-245ca, and then the cylinder is placed in a constant temperature bath until the temperature comes to equilibrium at 25° C., at which time the vapor pressure of the HFC-338q and HFC-245ca in the cylinder is measured. Additional samples of liquid are measured the same way, and the results are plotted in FIG. 1.

The curve which shows the composition of the vapor is calculated using an ideal gas equation of state.

Vapor/liquid equilibrium data are obtained in the same way for the mixtures shown in FIGS. 2-18.

The data in FIGS. 3-6 and 9-18 show that at 25° C., there are ranges of compositions that have vapor pressures higher than the vapor pressures of the pure components of the composition at that same temperature. As stated earlier, the higher than expected pressures of these compositions may result in an unexpected increase in the refrigeration capacity or efficiency for these compositions versus the pure components of the compositions.

The data in FIGS. 1, 2, 7 and 8 show that at 25° C., there are ranges of compositions that have vapor pressures lower than the vapor pressures of the pure components of the composition at that same temperature. These minimum vapor pressure compositions are useful in refrigeration, and may show an improved efficiency when compared to the pure components of the composition.

The novel compositions of this invention, including the azeotropic or azeotrope-like compositions, may be used to produce refrigeration by condensing the compositions and thereafter evaporating the condensate in the vicinity of a body to be cooled. The novel compositions may also be used to produce heat by condensing the refrigerant in the vicinity of the body to be heated and thereafter evaporating the refrigerant.

The compositions of the present inventions are useful as blowing agents in the production of thermoset foams, which include polyurethane and phenolic foams, and thermoplastic foams, which include polystyrene or polyolefin foams.

A polyurethane foam may be made by combining a composition of the present invention, which functions as a blowing agent, together with an isocyanate, a polyol, and appropriate catalysts or surfactants to form a poylurethane or polyisocyanurate reaction formulation. Water may be added to the formulation raction to modify the foam polymer as well as to generate carbon dioxide as an insitu blowing agent.

A phenolic foam may be produced by combining a phenolic resin or resole, acid catalysts, a blowing agent of the present invention and appropriate surfactants to form a phenolic reaction formulation. The formulation may be chosen such that either an open cell or closed cell phenolic foam is produced.

Polystyrene or polyolefin foams may be made by extruing a molten mixture of a polymer, such as polystyrene, polyethylene or polypropylene), a nucleating agent and a blowing agent of the present invention through an extrusion die that yields the desired foam product profile.

The novel compositions of this invention, including the azeotropic or azeotrope-like compositions, may be used as cleaning agents to dean, for example, electronic circuit boards. Electronic components are soldered to circuit boards by coating the entire circuit side of the board with flux and thereafter passing the flux-coated board over preheaters and through molten solder. The flux cleans the conductive metal parts and promotes solder fusion, but leave residues on the circuit boards that must be removed with a cleaning agent. This is conventionally done by suspending a circuit board to be cleaned in a boiling sump which contains the azeotropic or azeotrope-like composition, then suspending the circuit board in a rinse sump, which contains the same azeotropic or azeotrope-like composition, and finally, for one minute in the solvent vapor above the boiling sump.

As a further example, the azeotropic mixtures of this invention can be used in cleaning processes such as described in U.S. Pat. No. 3,881,949, or as a buffing abrasive detergent.

It is desirable that the cleaning agents be azeotropic or azeotrope-like so that they do not tend to fractionate upon boiling or evaporation. This behavior is desirable because if the cleaning agent were not azeotropic or azeotrope-like, the more volatile components of the cleaning agent would preferentially evaporate, and would result in a cleaning agent with a changed composition that may become flammable and that may have less-desirable solvency properties, such as lower rosin flux solvency and lower inertness toward the electrical components being cleaned. The azeotropic character is also desirable in vapor degreasing operations because the cleaning agent is generally redistilled and employed for final rinse cleaning.

The novel compositions of this invention are also useful as fire extinguishing agents.

In addition to these applications, the novel constant boiling or substantially constant boiling compositions of the invention are also useful as aerosol propellants, heat transfer media, gaseous dielectrics, and power cycle working fluids.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling point of -60 to +60° C., hydrofluorocarbonalkanes having a boiling point of -60° to +60° C., hydrofluoropropanes having a boiling point of between -60° to +60° C., hydrocarbon esters having a boiling point between -60° to +60° C., hydrochlorofluorocarbons having a boiling point between -60° to +60° C., hydrofluorocarbons having a boiling point of -60° to +60° C., hydrochlorocarbons having a boiling point between -60° to +60° C., chlorocarbons and perfluorinated compounds, can be added to the azeotropic or azeotrope-like compositions described above.

Additives such as lubricants, corrosion inhibitors, surfactants, stabilizers, dyes and other appropriate materials may be added to the novel compositions of the invention for a variety of purposes provides they do not have an adverse influence on the composition for its intended application. Preferred lubricants include esters having a molecular weight greater than 250. 

I claim:
 1. An azeotrope or azeotrope-like composition consisting essentially of:20-80 weight percent 1,1,1,2,2,3,3,4-octafluorobutane and 20-80 weight percent 1,1,2,2,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is lower than the vapor pressure of the individual components; 10-52 weight percent 1,1,1,2,2,3,3,4-octafluorobutane and 48-90 weight percent 1,1,2,3,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is lower than the vapor pressure of the individual components; 20-80 weight percent 1,1,1,2,3,4,4,4-octafluorobutane and 20-80 weight percent 1,1,2,2,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is lower than the vapor pressure of the individual components; - 52weight percent 1,1,1,2,3,4,4,4-octafluorobutane and 48-92 weight percent 1,1,2,3,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is lower than the vapor pressure of the individual components; 70-99 weight percent 1,1,1,2,2,4,4,4-octafluorobutane and 1-30 weight percent 1,1,2,2,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is higher than the vapor pressure of the individual components; 95.5-99 weight percent 1,1,1,2,2,4,4,4-octafluorobutane and 1-4.5 weight percent 1,1,2,3,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is higher than the vapor pressure of the individual components; or 20-99 weight percent 1,1,1,2,2,4,4,4-octafluorobutane and 1-80 weight percent 1,1,1,2,3-pentafluoropropane, wherein at about 25° C., the vapor pressure of the composition is higher than the vapor pressure of the individual components.
 2. The azeotropic or azeotrope-like composition of claim 1 wherein at 25° C., when 50% of the original composition has been removed, the vapor pressure of the remaining composition changes by less than about 10%.
 3. A process for producing refrigeration comprising condensing the composition of claims 1 or 2 and thereafter evaporating said composition in the vicinity of the body to be cooled.
 4. A process for producing heat comprising condensing the composition of claims 1 or 2 in the vicinity of a body to be heated and thereafter evaporating said composition. 